Angle that is smaller than a right angle (less than 90Â°). Angle formed by two lines or two perpendicular planes that measures 90Â°. Symbol denoting that a straight line meets another at a right angle. Symbol denoting that two straight lines do not remain at a constant distance from one other. Symbol denoting that two straight lines remain at a constant distance from one another.
Constriction vs. Dilation. Constriction and dilation are opposite, but related, processes in the body. Whereas dilation is an opening or widening of a structure or passageway to increase material flow, constriction leads to a decrease in material flow by closing the passage.
Report Abuse. 1  Contraction Grammar. 2  The opposite of contraction would be expansion, but that's not applicable in this case. 3  This Site Might Help You.  i think contraction means something expands , so constriction would mean the 1  opposite. i think a contration is a aposstrophe.